For centuries people have used various types of floor decorations in order to decorate their living areas. For instance, mosaic floors have been made using chips of stone, glass, wood, and ceramic materials or the like which have a wide variety of colors. However, it has been difficult to uniformly arrange these small chips onto a substrate layer.
In the past, the first step in preparing mosaic flooring using the various types of chips discussed above involves suitably arranging the chips on a substrate and applying heat and pressure. The pressure is applied by using a press or a roller so that the chips will adhere to the substrate and maintain their predetermined arrangement. However, the chips often overlap and lose their desired arrangement. Therefore, the aesthetic value of the final product and the productivity for producing the final product are decreased.
More recently, in order to solve the abovementioned problems, a method for the arrangement of chips using vibrations has been invented. This method is an epoch-making development in the design of a process for preparing floor decorations. For example, U.S. Pat. Nos. 3,056,224 and 3,170,808 disclose a process for preparing mosaic floor decorations, which comprises dispersing mosaic-patterned chips onto a substrate which has been coated with an adhesive agent, passing the substrate through a vibrator which shakes the chips and arranges them uniformly so that none of the chips protrude, filling the areas between the chips with temperature-sensitive dry-powder resin materials, and applying heat under pressure to fuse the substrate. As a result, the chips are arranged and become adhered to the substrate and the abovementioned powder resin materials fill the areas between the chips.
Another useful process has been described in U.S. Pat. No. 3,265,548. This process comprises applying a sol type resinous composition to a substrate by passing the substrate through a coating apparatus, dispersing chips made of a plastic composition while vibrating the substrate with a vibrator located under the substrate which serves not only to uniformly disperse the chips but also to deposit the chips inside the resinous composition, heating the chips deposited inside the resinous composition, flattening the chip covered substrate with rollers while maintaining sufficient pressure to flatten the surface without changing the arrangement of the chips while maintaining the temperature below the fusion temperature, and conventionally embossing or grinding the chip covered substrate in order to remove uneven portions.
Similarly, using the same method as described above, a method has been developed wherein after dispersing the chips on a plate and vibrating the plate itself to arrange the chips roughly evenly, the plate was put on the substrate of the floor decorations and the substrate itself was vibrated in order to arrange the chips uniformly. Furthermore, a process has also been developed which comprises passing the chips which have been roughly arranged in the same vibrating manner as described in the above process between a pair of rollers, wherein the gap of the rollers is adjusted to arrange the chips uniformly. However, there are such problems in the former method that the arrangement condition has to change according to thickness deflection and surface tension of the substrate which is being used. In addition, problems with the latter process include a situation wherein the chips do not appear to be naturally arranged because of the large space between the chips.